Bone Health in Premenopausal Chinese Patients after Adjuvant Chemotherapy for Early Breast Cancer

Background: In this cohort study, the objectives were to determine bone mineral density (BMD) and potential associated factors for bone health among young premenopausal patients after adjuvant chemotherapy. Methods: Eligibility criteria included premenopausal Chinese aged <45 years who had received adjuvant chemotherapy. At study entry, background demographics and menstrual history were collected; BMD was measured. Factors associated with reduced BMD and fracture risk were analyzed. Results: A total of 271 patients entered the study. The median time from breast cancer diagnosis to study entry was 5.0 years. The median ages at breast cancer diagnosis and at study entry were 41 and 47 years, respectively. The median BMDs for femoral neck (FN) and lumbar spine (LS) were 0.72 and 0.91 g/cm2, respectively; 40.2% had abnormal Z-scores (defined as ≤–1) and 50.2% had osteopenia/osteoporosis of either FN or LS. On multivariate analyses, factors that were identified to have a positive association with bone health (higher BMD) included higher family income (OR [95% CI] for LS = 1.573 [1.091–2.268]), taller stature (OR for LS = 2.975 [1.723–5.137]), and higher BMI (OR for FN = 2.156 [1.599–2.907]), while negatively associated factors included longer interval since last adjuvant treatment (OR for LS: 0.435 [0.250–0.757]), peri-/postmenopausal status at study entry (OR for LS = 0.443 [0.255–0.768]; OR for FN = 0.353 [0.205–0.609]), and having received adjuvant tamoxifen (OR for FN = 0.452 [0.243–0.841]). Conclusion: About 5 years after breast cancer diagnosis and adjuvant chemotherapy, >50% of premenopausal patients who had received adjuvant chemotherapy were detected to have osteopenia/osteoporosis and 40% had abnormal Z-scores for FN/LS.